Django REST Framework and FileField absolute url on the same field

Question

DRF serializes by default a filefield or imagefield path to it's relative path.

Like in this questions Django REST Framework and FileField absolute url

I know it's possible to generate a custom field called i.e. "file_url" and serialize the full path.

But is it possible to serialize it in the same field? like:

class Project(models.Model):
    name = models.CharField(max_length=200)
    thumbnail = models.FileField(upload_to='media', null=True)

class ProjectSerializer(serializers.HyperlinkedModelSerializer):

    class Meta:
        model = Project
        fields = ( 'id' ,'url', 'name', 'thumbnail')

class ProjectViewSet(viewsets.ModelViewSet):
    queryset = Project.objects.all()
    serializer_class = ProjectSerializer

{
    "id": 1, 
    "url": "http://localhost:8000/api/v1/projects/1/", 
    "name": "Institutional", 
    "thumbnail": "ABSOLUTE URL"
}

Answer 1

You could override to_representation method and write an absolute path there:

class ProjectSerializer(serializers.HyperlinkedModelSerializer):

    class Meta:
        model = Project
        fields = ( 'id' ,'url', 'name', 'thumbnail')

    def to_representation(self, instance):
        representation = super(ProjectSerializer, self).to_representation(instance)
        domain_name = # your domain name here
        full_path = domain_name + instance.thumbnail.url
        representation['thumbnail'] = full_path
        return representation